If you have access to Cook's Illustrated, they have done extensive experimentation with cookie leaveners. Baking soda makes cookies more crispy, but does not cause a rise unless an acid is used in the dough. Baking powder causes rise, but your cookies could be too puffy and doughy if you use too much.

Shuna is a pastry chef in New York City and author of the acclaimed blog Eggbeater.

added over 3 years ago

Making your own baking powder is really easy and a fantastic solution if you can't find non-alluminated in your area. Baking powder is considered a stronger leavening agent than baking soda. Baking soda can be found in most "creaming method" cookies (such as Chocolate Chip or Snickerdoodle) because brown sugars are high in acid, but sometimes a smaller amount of baking powder will create the same rise.

It's important to know that baking poder makes recipes stale faster and, for many people, tastes bitter or metallic. I prefer less rise and use Rumford baking powder or make my own.